After years of imprisonment in Asgard, Loki escapes to Earth to gain his revenge on his half-brother, Thor. Once there, Loki learns that Thor lives among humans as one of them, Dr. Donald Blake.
Loki enhances the mental powers of Sandu, a carnival mystic. Sandu then uses his supernatural powers of levitation to battle Thor and to trap him beneath an entire building.
Hoping to break up the love between Thor and Jane Foster, Odin heeds advice from Loki. Loki uses this opportunity to pit the Enchantress, the Executioner and two powerful giants against Thor.
Loki brings Jane Foster to Asgard and tries to convince Odin that it was Thor who brought her there. In order to prove which of his sons is lying, Odin sends both to Skornheim, where they must endure its deadly dangers.
Escaped convict Crusher Creel is given power by Loki to absorb the properties of anything that he touches. As the Absorbing Man, Creel uses his fantastic strength to battle Thor.
Loki lures a hunter into The Temple of Darkness, a hidden tomb where the hunter's spirit enters the body of the Indestructible Destroyer, an enchanted suit of armor forged by Odin.
Scientist Paul Duval gains the power to turn himself (and whoever he touches) into living stone. As the Grey Gargoyle, he attacks Thor hoping to steal Thor's magic hammer, which he believes will help him gain immortality.
Zarrko, the Tomorrow Man, travels back in time to 1962 to steal a cobalt bomb that he plans on using to make himself ruler of the 23rd century. Thor follows him forward to 2262 in order to defeat him.
When the Greek god Hercules arrives on Earth, he takes a fancy towards Thor's love Jane Foster. An enraged Thor fights it out with Hercules all over New York City.
Tricked into signing a contract to become the ruler of the underworld, Hercules must rely upon Thor to champion his cause and help him to win his freedom.
When a race of underground lava men threaten the surface world with destruction, Thor gathers his Avenger teammates in an attempt to thwart the attack. The group is aided by an unlikely ally, their former team member, the Incredible Hulk.
In this first episode we find out the origin of Prince Namor, the Sub-Mariner. Having incurred amnesia because of an illness, Namor looks for his identity on land and finds the mysterious Mrs."B", who knows & holds the real truth of his past.
Prince Namor encounters dangers and traps in his quest for the fabled Trident of Neptune. Evil Krang tries his best to stumble the Sub-Mariner as Lady Dorma pines for her beloved Prince.
A ship's captain concocts a liquid to subdue the people of Atlantis while he steals the gold condinium under their streets. Namor must get the help of Dr. Debrik if he is to wake his people.
A quick recap of how Steve Rogers became Captain America. Captain America's main focus is on saboteurs as he keeps his identity secret disguised as an army private. The Captain later learns that the Red Skull is behind the sabotage.
A mysterious sword wielding man breaks into Avengers headquarters and demands to be allowed to join. After the heroes defeat him, he concocts a plan to kidnap Captain America.
Captain America leads the Avengers into Sin-Cong to answer a distress call, only to find it's a trap set by the nation's superhuman leader, the Commissar.
Bruce Banner becomes the Hulk by saving Rick Jones from a gamma bomb explosion. The Gorgon comes to America and fights the Hulk, only to be cured of his ugly disease by Hulk.
After the army shoots down their UFO, the evil Toadmen seek refuge in an underground tunnel and magnetically pull the moon toward earth, causing great disasters. Banner escapes imprisonment, confronts the Toadmen's attack and saves earth.
The Leader, a mutated super villain, learns that Doctor Banner's newest nuclear device is being transported to another military base by a train, and sends one of his Humanoids to attack the train and steal the invention.
The Hulk is displaced by the Space Phantom, causing the breakup of the Avengers. The Avengers unite to fight the Phantom, but Hulk leaves the group, disgruntled by their attitude toward him.
General Ross transports Banner into the future with a T-Gun, where he fights a futuristic army and faces a godlike executioner. Rick Jones tells Talbot that Bruce Banner is the Hulk.
Boomerang tries to steal a missile from General Ross' base and kidnaps Betty along the way, only to give her to the Hulk after a fight. Boomerang attacks an army base, but Talbot stops him. Will the Hulk ever be a hero?
The earth starts swallowing buildings and the government thinks Tony Stark's new earth digger is responsible until Stark's factory is swallowed along with Iron Man.
When the press discovers that Tony Stark is Iron Man, Happy puts on the armor to fool them. He quickly gets kidnapped by The Mandarin and Tony must make new armor to save him.
When Happy is injured in a car wreck, the villainous Black Knight abducts him from the hospital and uses him as bait to lure Iron Man to his castle-fortress.
Upset about Pepper's love for Tony and Tony hogging the spotlight, Happy quits and goes to Ireland. Iron Man tries to convince him to return while being randomly attacked by old enemies he believed were dead.